http://myanimelist.net/anime/8841/Ko...Zombie_Desu_ka
https://www.youtube.com/watch?v=fllrvN-OAnw Anime opening
Aikawa Ayumu will fight a enemy cross dressing in a Mahou Shoujo outfit(albeit very reluctantly) if his zombie abilities are insufficient for the task.
In Kore wa Zombie Desu ka? novels 11 and 12 Ayumu is turned into a girl after his male friend Orito gets his wish magically granted. I don't know what he does to change back.
Volume 11
http://i.imgur.com/FI4pBaw.jpg
http://i.imgur.com/04aNApD.jpg
http://i.imgur.com/toWhm4c.jpg
Volume 12
http://i.imgur.com/gLIZMiq.jpg
http://i.imgur.com/mTxxRlx.jpg
The cover for volume 19 features female Ayumu in his Mahou Shoujo outfit. I don't know the details about volume 19 except that all of Ayumu's love interests have settled down with him and that the next volume will be the last.
Volume 19
http://i.imgur.com/f2t6NNw.jpg
http://i.imgur.com/SwpwSH1.jpg (Fan Art)
On a personal note I think Ayumu would prefer to be a girl when he is a Mahou Shoujo. It would certainly be less humiliating than wearing a Mahou Shoujo outfit as a guy.